5 Green Cities of the Future

No cars, no waste, no pollution. Doable? Such a city is slated to rise from the oil-rich grounds in Abu Dhabi. Masdar, which means "the source" in Arabic, is a $22-b­illion undertaking that could be the world's first carbon-neutral city [source: Masdar].

Masdar's sustainable urban development will take advantage of wind, hydrogen and solar-photovoltaic energy sources. Wastewater will be treated and recycled into irrigation systems.

­In addition, Masdar's transportation goals are ambitious. Fossil-fuel burning cars are banned from the city in lieu of an electric personal light-rail system -- small, programmable cars that run only when you need to go somewhere, and a pedestrian-friendly city layout.

Masdar is already under construction and will develop over several phases, with completion expected in 2016 [source Inhabitat]. Up to 50,000 people are expected to live in Masdar, and the first residents will likely move in sometime during 2009 [CNET].

The time of the carbon-neutral city is upon us. And if these projects make the jump from paper to reality successfully, they might even earn a spot on our list of existing amazing green cities. ­

Green Mountain Resort, Libya

Cyrene, Libya, an area about the size of Wales, may be one of the next carbon-neutral developments in the world. The Green Mountain Sustainable Development Area is a new eco-friendly project in a remote coastal region of the country. The resort, intended to boost tourism, would draw on renewable energy sources, specifically wind and solar power, sustainable transportation and housing, as well as closed-loop water systems.